What happens if a user turns off Cookie within a GA session

I am curious what happens if a user starts a GA session and let's say 1 minute later, the user turns off the Cookie, how is the information of that Session being recorded on GA?

I am curious if this would be the reason for the observation shown as the last record below:

As for the last record, I have 1 user but 0 session or 0 pageviews.

The first column is a user level customer dimension which indicates the user's Business Persona. The Persona information is passed from GTM via a data layer variable.

Any insight on the Cookie question as well as the abnormality observed above?

Thanks! Yao

If the user has already entered on your site, then the session has started, because page view hit was sent to GA. Hit can't be recalled. Turning off the Cookie can affect only on next hits.

What about events? Events without page view don't start session. Sessions will be 0, but user will be counted.